SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a3966395bae8fd9b26c8a7095a26c6d5d9a75048627ad079810f9705124fada' 
  AND token = 'm/iKGb36jf6KmdwOysgAnYR1YIRKsx8PMt4mct4hrXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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