SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03c47a63ff353dd20eb2d163c7a3dc3717368250cad728f123ed4a232c7decdb' 
  AND token = 'ADSInoLkuiZML49gPUzCVpgDvOoPVAHix/BKWjSfs8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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