SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14ab0f832c477391e202e113b859e69da37ad694c56c342667edd8505fc4e81b' 
  AND token = 'TmNuv8fazevkUNY5ScMH+dFEi01MsNtHWCLo8T2MSNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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