SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2e7eb24ae234622094e54b64ad2b0bcb370f9ea4f5aa3e69e3117236c0db9eb' 
  AND token = 'WU5ivmrJ3tG7XnYv+Ct1h2SNgT8kX4KxAmelAenKxmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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