SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aaedd8ead48a2dec43ce381b9f6066544fad907cedfc72465c84a7441a67c10' 
  AND token = '+oHiSa37onErWurq8OKNUmq5Fn+OFBSVmJJtjtJJYhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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