SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b54de5fafc7032a87962d86d67bbbcd774dac9f75002abbd104e0fdcbb73c076' 
  AND token = 'T33jzR8NvMGEvc8yBGD3irCKcu0thx3CZwEus3wvkBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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