SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94529a807cb385974bb2b5902b4dfd78e8fc4c485cdf419bc574ac47864618a7' 
  AND token = 'r02i3iI/MphI7JvOp8EypfMsLCsQfSwqCV5PIOWSs6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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