SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b34667e0680483a06247f4bd2f4c1d1c4b7e92631d79060cacf8e236f90df557' 
  AND token = 'a9ZbC5aD7KHxQ8JVIhst36ooh7wUHwcwN6IQYzH4cjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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