SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96a4665e2cc739d6dff9360bf5efb5e955d2691514e0608c4a01080857176b7b' 
  AND token = 'Ua0PmhaEXUVRZWh3oW547DIsb5+w19DNLNtWAtlq8Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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