SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4898d6849bdca1ce319e6bba1d6bbadc95a4a07de814d95266802702d48221b1' 
  AND token = 'B4jHfdRD8aI4zFNrjQohZfWTMaqkE4W7fonqlL+GONg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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