SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcb0addbd7580de742ecbbc080d78c1bbb829c2a407418d102ecee6e88ccd288' 
  AND token = 'XWJAuuMYUeFKYX76D5wA1UgSBnzQYNQA5t2EGAlq6Zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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