SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6243e709f9761b41b70839f001f00df6b64d6d594c0a7bdf10a8a6a567e01532' 
  AND token = '6ZtjTl8haDFfX4m4YgYUxd1j/VRCQoAdzyfL5gUzzYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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