SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '924355d399af1fbb2903bec3db58e75b66c36f747fbbfde6fc1b924ddc3e5357' 
  AND token = 'fBzn1vM8j/t0lH+OeOi8OQVmznsCGEZfLVdVY41YftI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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