SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0a09d890988683debf6af3c2854081f9a2b9996b753319db0bc47e9750947f8' 
  AND token = 'lxFEGl3KT/+qANMHRVozyjz2/WNBxgxA+AXOhXUhKoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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