SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb9a247fea00f86b7069cc04cfcb48078893b2892912901f71271811a2bd280' 
  AND token = 'r3wdd+plHRih2nINV8lC1AqGELquuGfrffKqjBOOYSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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