SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12c56ce7c155c56e118b0f2df9cd16f91298976531f19e4e877ead1221d78730' 
  AND token = '93sEPnDvlsnxrE3nRwlj7ymTdsAVsndPI8XPPcb00I0=' 
  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"
    }
  }
}