SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f964827e5cf12963a662db42033f92460eaf1e12213850f5de7841ffc09c7a8' 
  AND token = 'qNoHWOZUhlH8tkQJ6GO8FOf+CE0Mwd69ge8u5/aMUeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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