SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4a4c08ea4ce78f5ceabdf29fd99618576437e72e29167a2be6becdc7cb2db93' 
  AND token = 'isTH4BeHEyFXPQB4hUJ110uDk2wBtyDipRocCEbQEyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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