SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a42ffbd8c30f007660330d436bdece62d907c8275be2b25cc15a3b3582d432d' 
  AND token = '/fhVGGKeZ1/+HXrgnAXCUNjEusL0J/ip18ZV9rbIiRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}