SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd72d5c3dfbb807258a43ae16c78391e74be4b7620daab11d425e71cc1f27860' 
  AND token = 'cTGECJIOYBlG0nXaCJjKHCTyrdtuNPzQXNiPdQuStps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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