SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5780bbdb98cdb6a3783b665ebf1fbdd4e3aaabe33be2ecede66c3f8534d1f10' 
  AND token = '4/4xAF2w/AyzhGNxCuqQEI+mJPw9zVhtSnHXVX8bdFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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