SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1472cfdadc24c948484618e4d79ab6fe05c28fe14938717b30621062511aeb7' 
  AND token = 'ltAwDmyMgUasMk9tbDc4PCUB9TvzmY18Zv8xJQvRLhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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