SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73f35549ed449a2a627fa8452df554f97730926fa6e15b081dca53f43287b02e' 
  AND token = 'r/2Qbm2BYXJ5KPwPuXCcMZ8V817TMl0VwHs8EuFq74M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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