SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bec967859d938a5ca336f88626b474f91a90678395bcb8618a3e613adc09644' 
  AND token = 'haXMH85v2Chujc/6Ik1YvpnjiRhMvSmxFz9EjPCZsE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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