SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82338a0d8078b526356831d2becbcf24358929eab58d8d3170b910207cc626d8' 
  AND token = '7U/t80LCUNbg1CJTfOoSNkJhcjaivN5y8yXLmquXZvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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