SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d2818db8a16991f1a1826dcefaa088b29313757ac1d7b4dda62837ed1826a5' 
  AND token = '77Jg8/IsymvCsO6w2phU/Np+lV5KirTmpHNaxByjzXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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