SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3e6466f3ccfad65ebe985f1cec7195a5a69c9045bf6ef873eb6d0739137fd55' 
  AND token = 'TyI9wR2dnIEQNCKVg72Y0Y7FP/Pl06OKspCN0XPLlvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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