SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b8116b622a54e4fc3b2df58921017c505cd568a379b5f682360f5617f6cec3c' 
  AND token = 'fCs+YrccLXSsRnpoHLVNkM8EBh7PzhNxZyj4JJK9rio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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