SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0b07d27cfeefeee9c3f5e8f29ed2b9fc9a86c1299f20be434ecc843db011774' 
  AND token = 'fO2jf6Kv4FIopZ86gQ4fKa5Pdi6ZCMUDQM1lLq/NIhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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