SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abbff4e5d8a1cbcc54426f484a8dd2a473d107f0148f491a5958f009585edff9' 
  AND token = 'PIKGhtjV2cyJm8RT0tXwQ5u9b6fAb+sdltrk7hkkWBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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