SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c499e29bd81848c135b60ba941211dcd8d5cdbe70603292b5534d7a2346fc142' 
  AND token = '5QeksOYQZSlVBrFP8nEmWuJ6i/vFkqVwUGVyoqa8T+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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