SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eb6e10b6314be92222a1f330b2cd4befb23b3756af4ac32c559930d966583f9' 
  AND token = 'QBD6eX01PlvJy3ZcFy8oF/MygoC3/a72EHDbSimMm0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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