SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a4b532e224ec8501c14ca93d85057f90536560a8a77e295255c934dde706c81' 
  AND token = 'tAIXc133n5SEPyAjYjpKmVHu6sIDyLuz26ihibiO7cM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}