SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7901fa89fa2f27fd5ceefae2969ca70c20e466ad3ff2db47a7dba8842fffe5c9' 
  AND token = 'jqJA5hXR8RopVze5pBndmKhYuOH+PpqVuvSoUDl61Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}