SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8b184e2d0c882c27660a0721f1adf44146f6682e49d23f686f95b25957ee63d' 
  AND token = 'f+lJ/6uq3FpPA4t87R0A1H0q5sqzeeOgDQfWIBJrKjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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