SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '62dafbc0b6f754b0a59276ed4247010b27122d5a9a12bc41ba134476a8f5daad' 
  AND token = 'I7sxbDBNiJOHNO5iq4cwGj5TK4NgXsZ5lnjqyZBdG7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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