SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a61d344e97844f0e8aae0a9cc461e604bcba396e3bd00dda0a1aabf4888108fb' 
  AND token = 'ZAkFw31CUZnhd/vRspWJxQl5vOUxVAh+a1+rSG4e2Qc=' 
  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"
    }
  }
}