SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0030ec53772d1ae08853712622edb9da4ecb172dd740d175772873b2079316a0' 
  AND token = 'ga3HMoO5/7ZxPbPGAUSbZ2EvZkoodSdUXhY0bsiWC8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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