SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33c8930fbd676f27458347c959c3a35943a3e567925967c232ece73b38b3a0a7' 
  AND token = 'LRXhZj0xKsUL9Hc6UbrdW407+Tnpg78owNT3+vF2ABk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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