SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c62ce0141b440c8cee3cd521b0b89438d3a9059a5140711dc4e279eedac6f4d' 
  AND token = 'GA67TC9rQiUjEio6myAOpoSBC0ssrs+RXUWYxdGms0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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