SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94c84ef9f9c0d185dbbeea638eb1f8a83af57746f1d3241bd395c9c237ad3f76' 
  AND token = 'Uy1/GP14/9FILYUiKQ3F5KnvgfgbiEU7AreONFvIDv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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