SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c22f6cf8b20d7670ba742660e31a5a718dd26f3c396fdff46e24a28aebe93828' 
  AND token = 'keeBJlBEr8TiX8WhaaED06kuN36FGL+XltBUl9CZGAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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