SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0218c991f58b3a05cd0ed0fd1e934738c98e3ffb2573b70dac64be5f9012a59' 
  AND token = 'UCwx7l+dvG+EAGNGfHuc32sW9JFFviEfFD19H7N+Gks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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