SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a74da5d45dc56d512d3ed0774195613f2a1f9ca3ded6e6054531a41dbcf53213' 
  AND token = 'fERLoFV22S3MSu9nKwL/ZPXCDNgq9qOeFGiw9EnQGLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}