SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b1bf2e33736efe2a290ef863a290afb19e7a118b8dbecf79ace31dc8f5838f9' 
  AND token = 'wtYRmHLhbe1gY/cfVVOfcN4RY3Zb8xSwlaK3EozeNEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00136

JSON explain

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