SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b891c16d5ace69674927be3eff850d6eda04049b1d4e1ad54d4b73fbc2546f9e' 
  AND token = 'cw8TxI9VCoxqVlrmMGVzdf58KUZWTki9aO4Yc5kKxEE=' 
  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"
    }
  }
}