SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ef1d81c8266d490ec0b44b900f337bd365e46518b245ac8fbc27570d04783c5' 
  AND token = 'JUjQKr9uPiXCRtFdcT/ColYC0V0MeXRRgqLh5sZFF1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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