SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87c4f28d82ec686fe5ae68d00c61e4f83cd2244ab2333e942ee9e8d4b709c5a9' 
  AND token = 'G9BvrHPPkjfLrAe8wksgOduVYHyHPANbUIJr5Hx3n4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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