SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2972dbae555ea7252090bcfb0db12edf688a813cfba2759265ad050bc4c69166' 
  AND token = 'rMggnpICUtiBMIXfISMbIResHjtQlEVQZKsJ95QyJR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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