SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9534b2f7ea49f110b58de34ee68146e249d8cdfdf3fb3547646a51d151562fbf' 
  AND token = '8SLUWA+y7jLysgrxPID1lcJzIyxekBNX7+QfyZtAdXc=' 
  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"
    }
  }
}