SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab4759194c44c8187dab526ed4aa0383c458f4fb866d9f2363ed7e60ccf2d379' 
  AND token = 'HBnD8yTOWKECUTSfxmuV/z4ShMp1kED+4mMztY6zRj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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