SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31c75b0659020a69745293031618c5df14ea3756b30a553a5728de7e3558c63a' 
  AND token = '19QecBELBKeOxwGrspnbeLTQ0mvfZp608mnGk6uj4CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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