SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c89c07a4b2eade9177f0b593b3cb6e663dcfade129831e323031e165638aa59' 
  AND token = 'QVweukV519MAjuqTYrRLoNN72qUe+ez47e+aJNIvkPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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