SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23de62a0f14c18b995d683c163a364f0c8a8b8a3601a675715928d0b4259b25e' 
  AND token = 'ZRUrTHxnLNiKgD0c14KBxqGfVjTpdb6liMxyVAIxaUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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