SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac3f16811a0bb921b3f3164ebfd7e6253a55f2d483f11ce62f74ed771479e060' 
  AND token = '7QVEcOcQiyhknXsU9CI0Tn0acYEi7iVUATVEhye9DYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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