SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d946538fd76777ee894b4556959a500944597a4b08df8d28d79be1ea7488e2b' 
  AND token = 'pLHinbYeWbBamJGgFOtoYsDLuMVT5nVQ3iH6iSY2POc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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