SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7653b6cb691a34a6e1531617fd847f25e0589f9cc2ba6934324ab23cd896cb2c' 
  AND token = 'bWNjJjQZm3nPtpHfOj+lnLKd0zBdnlTpebaLvHy1DOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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