SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc2309142fbd2471e59403fdc7ace653deb280257bae1c3298b214c8357bc0e8' 
  AND token = 'ODlfggqxripBcPwAyjjQzFm8rtPaEk+CfVZ200NKDgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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