SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ec98d948ff1c6e7c0ef378adce5d73cfe10fbc9dfc3c2ec38c77b38294412d0' 
  AND token = 'P6BgtqVqfvBrjQD/DaI4lQd+CgpwUGpuCgWFmHMg9HQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00292

JSON explain

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