SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b8e058f86ae99f1cc6a709366236b961c4d7d1e2535479f3cdf9f7f2c5ccbff' 
  AND token = 'VR1o2v8yCS2ML4HsJOFHwB5nxCkKEOquG5JtjI+s8+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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