SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '10684dd2104bc2861172cec83f67b3f7f2a4507148175a2188161c0f975f5d29' 
  AND token = '4CKdGLJInXEz6IPTE2kI/k6AxBnFgbm62JhHp8BHyyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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