SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52679b5f807dd9b98c118c156b42715caf5d142f04e63cabf6830e5e67fa1638' 
  AND token = 'T+1paq/5+wl9F47dEEqF5gKJuZPVAPcUM0M39GeALbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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