SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61be61d60cb8ffcaa7b5269a1115d2c01f81cb62352c26fccf6cfb05fadbf7a9' 
  AND token = 'P8DkQipYngh5eiVbFZ3mWFrRNcIOvJh8FGYbxq6jq1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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